# Problems with ssh connections to hosts behind jumphost **URL:** \ **Category:** Ansible Project\ **Created:** [June 18, 2016, 3:11pm UTC](https://forum.ansible.com/t/problems-with-ssh-connections-to-hosts-behind-jumphost/21807 "2016-06-18T15:11:48Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Johannes\_Kastl](https://avatars.discourse-cdn.com/v4/letter/j/bbe5ce/32.png) [@Johannes\_Kastl](https://forum.ansible.com/u/Johannes_Kastl)\ **Post date:** [June 18, 2016, 3:11pm UTC](https://forum.ansible.com/t/problems-with-ssh-connections-to-hosts-behind-jumphost/21807/1 "2016-06-18T15:11:48Z")
Dear all, I have some hosts that I can only reach via a jumphost. So, my .ssh/config contains: Host foobar   ...   ProxyCommand ssh -W %h:%p whatever   ... I have a strange, intermittent issue, that I can connect to one of these hosts via ansible and run a playbook. Running it on more than one host fails out, sometimes "unreachable", sometimes module errors. Re-running the playbook on the failing host only works. Any hints, how to solve this? Or how to look for the error? I thought about checking ssh multiplexing, pipelining and similiar stuff, but without an idea where to look I'm kind of in the dark here... Any help would be highly appreciated! Johannes ---
**Author:** ![sivel](https://sea1.discourse-cdn.com/ansible/user_avatar/forum.ansible.com/sivel/32/1198_2.png) [@sivel](https://forum.ansible.com/u/sivel)\ **Post date:** [June 18, 2016, 3:18pm UTC](https://forum.ansible.com/t/problems-with-ssh-connections-to-hosts-behind-jumphost/21807/2 "2016-06-18T15:18:03Z")
You may want to look into raising the MaxStartups sshd config on the bastion. Maybe also look into increasing `timeout` in Ansible.cfg ---
**Author:** ![Johannes\_Kastl](https://avatars.discourse-cdn.com/v4/letter/j/bbe5ce/32.png) [@Johannes\_Kastl](https://forum.ansible.com/u/Johannes_Kastl)\ **Post date:** [June 18, 2016, 3:28pm UTC](https://forum.ansible.com/t/problems-with-ssh-connections-to-hosts-behind-jumphost/21807/3 "2016-06-18T15:28:31Z")
Thanks Matt, that was quick! > You may want to look into raising the MaxStartups sshd config on the > bastion. I'll try 100:30:300 and see, thanks for the suggestion. > Maybe also look into increasing `timeout` in Ansible.cfg I already did that, but to no avail... Johannes ---
**Author:** ![Johannes\_Kastl](https://avatars.discourse-cdn.com/v4/letter/j/bbe5ce/32.png) [@Johannes\_Kastl](https://forum.ansible.com/u/Johannes_Kastl)\ **Post date:** [June 19, 2016, 1:35pm UTC](https://forum.ansible.com/t/problems-with-ssh-connections-to-hosts-behind-jumphost/21807/4 "2016-06-19T13:35:52Z")
Although timeout is set to 30s and MaxStartups is set to 100:30:300, I still have intermittent failures. I tried to set 'serial: 2' in the group\_vars, but I am not sure if this has to be set on play level. Off to read the docs.. Johannes ---
**Author:** ![Mirko\_Friedenhagen](https://avatars.discourse-cdn.com/v4/letter/m/838e76/32.png) [@Mirko\_Friedenhagen](https://forum.ansible.com/u/Mirko_Friedenhagen)\ **Post date:** [June 19, 2016, 6:37pm UTC](https://forum.ansible.com/t/problems-with-ssh-connections-to-hosts-behind-jumphost/21807/5 "2016-06-19T18:37:31Z")
One thing which once hit me: on MacOSX the file ulimit was only 256. I have about 140 hosts and when our company decided to use a jump host I suddenly ran into problems because the pipelined connections now hit this limit. Regards Mirko ---
**Author:** ![Johannes\_Kastl](https://avatars.discourse-cdn.com/v4/letter/j/bbe5ce/32.png) [@Johannes\_Kastl](https://forum.ansible.com/u/Johannes_Kastl)\ **Post date:** [June 19, 2016, 7:06pm UTC](https://forum.ansible.com/t/problems-with-ssh-connections-to-hosts-behind-jumphost/21807/6 "2016-06-19T19:06:53Z")
Hi Mirko, ---
**Author:** ![Bogdan\_Mihaescu](https://avatars.discourse-cdn.com/v4/letter/b/b9bd4f/32.png) [@Bogdan\_Mihaescu](https://forum.ansible.com/u/Bogdan_Mihaescu)\ **Post date:** [June 23, 2016, 9:57am UTC](https://forum.ansible.com/t/problems-with-ssh-connections-to-hosts-behind-jumphost/21807/7 "2016-06-23T09:57:40Z")
Hello, I have the same problem. Did you find any solution for this ? Thanks ---
**Author:** ![Johannes\_Kastl](https://avatars.discourse-cdn.com/v4/letter/j/bbe5ce/32.png) [@Johannes\_Kastl](https://forum.ansible.com/u/Johannes_Kastl)\ **Post date:** [June 23, 2016, 6:56pm UTC](https://forum.ansible.com/t/problems-with-ssh-connections-to-hosts-behind-jumphost/21807/8 "2016-06-23T18:56:47Z")
As the hosts are lxc containers running on the jump host (and only being available via the jump host), I guess it might be due to memory usage when the commands are being run on all hosts simultaneously. I'm in the middle of trying out some things, but no, a real solution did not present itself. Try (and maybe disable) ssh multiplexing, pipelining and starting the playbooks with forks and/or serial... Johannes